1. Field of Invention
The present invention relates to a trace detecting sensor, and more particularly to an optical trace detecting module with an optical path diverting element.
2. Related Art
With the development and advancement of technology, computer equipment, no matter it is a Personal Computer (PC) or a Notebook computer, has become a convenient and indispensable tool for people's daily life or work. However, only with a cursor input device such as a mouse, touch pad, tracking ball can the computer equipment perform the control of the window interfaces of the computer equipment.
Take an optical mouse as an example. An optical mouse emits lights from an optical sensing module mounted at the bottom of it, the lights are reflected from a surface of an object to an optical sensor of the optical sensing module, and the optical sensor detects the variation of the lights reflected from the surface of the object, thereby generating a corresponding cursor moving signal. For example, if a user intends to control the scrolling of window pages, he/she still has to rotate the wheel disposed at the top of the mouse to cause an encoder connected to the wheel to output a control signal, so as to control the scrolling of the window pages up and down correspondingly.
In recent years, Touch Control modules that have cursor control functions and can perform preset functions have been developed, and those functions have entirely replaced the functions of the optical sensing modules and buttons of the conventional mouse. A Touch Control module is disposed at an upper casing of a mouse. A user can control the position of the cursor selectively by the optical sensing module at the bottom of the mouse, or by a finger sliding on the Touch Control module, thereby generating a corresponding control signal.
Various optical elements in a conventional Touch Control module are stacked to form a completed optical path. Accordingly, the irradiating distance between the light emitting diode and the optical sensor must be lengthened relatively, such that the lights emitted by the light emitting diode can be refracted into the optical sensor accurately. Multiple optical sensors and optical systems have to be used to generate the scrolling control signal from a finger sliding on the Touch Control module and the cursor control signal from the bottom of the mouse displacing on a plane, respectively, which causes the space occupied by the Touch Control module increased accordingly, such that the volume of an electronic device equipped with a Touch Control module is greatly increased and the device cannot be thin. As a result, recently, other than applying to a computer cursor input device such as a mouse, the Touch Control module is difficult to be carried in a portable electronic device such as a cell phone, personal digital assistant (PDA), and flat panel computer.
In addition, a conventional Touch Control module has multiple optical sensors and optical systems. Therefore, the design of the wirings between various parts and the Touch Control module in a mouse must be considered, thus resulting in the increased number of the process sequences. Moreover, optical sensors are expensive such that the prices of electronic devices equipped with a Touch Control module are high, which cannot satisfy the recent demands of consumers that the electronic devices must be light, thin and cheap.
Taiwan Patent No. M304078 discloses a cursor control mechanism. A light source in the mechanism emits a light beam that is incident at one side of a spectroscope, and the light incident to the spectroscope is split into two light beams. One beam follows its original path to project to the surface of a sphere, and the other beam is refracted downwards to the operating desktop of the mouse, so as to retrieve an image through an image sensor.
Although the Patent No. M304078 addressed the problem that multiple sensors must be disposed in the mouse, after the two light beams from the spectroscope are incident to the sphere and the operating desktop respectively, scattering occurs. Furthermore, the scattered light beams are reflected to the light source, thus resulting in undesirable optical sensing efficiency of the mouse.